slit v.

c. 1300, sclice, "a splinter, a fragment," from Old French escliz "splinter, broken piece of wood" (Anglo-French sclice, Modern French éclisse), a back-formation from esclicier "to splinter, shatter, smash," from Frankish *slitan "to split" or some other Germanic source (compare Old High German slihhan; see slit (v.)).

The meaning "thin, broad piece cut from something" emerged early 15c., with thereafter many technical applications to specific thin, broad things. Slice of life (1895) translates French tranche de la vie, a term from French Naturalist literature.

1670s, "showy brilliance," from French éclat "splinter, fragment" (12c.), also "flash of brilliance," from eclater "burst out; shine brilliantly; splinter, fly to fragments," from Old French esclater "smash, shatter into pieces," which is of uncertain origin, perhaps from a Germanic word related to slit (v.) and to Old High German skleizen "tear to pieces; to split, cleave." Extended sense of "conspicuous success" is first recorded in English in 1741.

late 14c., earlier sclat (c. 1300), "a roofing slate; a thin, flat stone," from Old French esclat "split piece, chip, splinter" (Modern French éclat), a back-formation from esclater "to break, splinter, burst," which probably is from Frankish *slaitan "to tear, slit" or some other Germanic source (compare Old High German slizan, Old English slitan; see slit (v.)). The meaning was extended to "long, thin, narrow piece of wood or metal" by 1764.